Plastic container with flexible hinge



Jan. 26, 1965 J. B. KRUGER ETAL PLASTIC CONTAINER WITH FLEXIBLE HINGE 5 Sheets-Sheet 1 Filed May 23 1962 1965 J. B. KRUGER ETAL PLASTIC CONTAINER WITH FLEXIBLE HINGE 3 Sheets-Sheet 2 Filed May 23 1962 I ll Ell llll/lll///lll//l/ u u u a 26, 1965 J. B. KRUGER ETAL 3 0 PLASTIC CONTAINER WITH FLEXIBLE HINGE Filed May 25, 1962 3 Sheets-Sheet 3 United States Patent 3,167,207 PLASTIC .QGN'IAINER WITH FLEXIBLE HENGE Jarnes B. Kruger and Paul A. Braginetz, Staunton, Va, assignors to Philip Morris Incorporated, New York, N.Y., a corporationef Virginia Filed May 23, 1962, Ser. No. 196,953 Claims. (Cl. MIL-31) This invention relates to a plastic container having a base section connected to a cover section by means of an improved hinge assembly. More particularly, the present invention relates to an easily assembled plastic container comprising a base section and a cover section connected together by means of a separate flexible hinge.

A need has existed in the art for an inexpensive, readily assembled plastic container and a great variety of constructions have been employed or suggested. In some cases the hinge arrangements have been relatively complex. Many require auxiliary fastening means such as glue, screws, bolts or the like. Some have embodied relatively rigid hinge assemblies which were easily snapped off or otherwise broken. Ditficulties have been encountered in providing a suitable but simple hinge means particularly where it is desired that one or both of the sections comprising the base and cover be made of transparent material. It has heretofore been proposed to cast the hinge as an integral part of the container but this encounters the disadvantage, in many cases at least, that any one material may not be compatible or suitable for the different properties required or desired for the sections of the main container and the hinge means respectively.

It is a primary object of the present invention to provide a readily assembled inexpensive container in which the parts or elements are especially adapted for their respective functions or properties. The base section and the cover section may each be made of a material which possesses the desired properties such as rigidity, transparency or opaqueness, or of a selected color. The hinge proper, however, may be selected for other properties such as flexibility, long life under repeated flexing, and ease of manufacture.

It is a further object ofthe present invention to provide an improved hinge assembly for connecting the cover sec tion of a container to the base section of a container which is of simple construction and which is easily assembled without the use of auxiliary fastening devices.

his a further object of the present invention to provideaplastic'cont-ainer and hinge assembly which are of attractive appearance and which possess good wearing qualities, whereby the hinge can be repeatedly flexed for long periods of time.

Gther and more specific objects and advantages of the present invention will be apparent from the detailed description which follows, when taken in connection with the accompanying drawing. The drawing illustrates, by way of example, certain preferred embodiments of the invention. It should be understood, however, that the drawing is solely for the purposes of illustration and it is not intendedto restrict the invention to the particular embodiments shown.

In the drawing:

FIG. 1 is a perspective view of a container in accord ance with this invention showing a tray or base section, a cover section and hinge assemblies, one of which is shown disassembled.

FIG. 2 is a partially cut away, enlarged, perspective view of the hinge portion of a hinge assembly shown in FIG. 1.

FIG. 3 is an elevational view of the inner face of the hinge of FIG 2.

4 is a sectional side view of the hinge of FIG. 3 taken on the plane i4 thereof.

FIG. 5 shows a section of the container and hinge assembly of FIG. 1, with the hinge assembly partially cut away to reveal the position of the parts when the base and cover are in closed position.

FIG. 6 is a partial view of the container of FIG. 1, showing the hinge assembly and portions of the base and cover, when the base and cover are in an openposition.

FIG. 7 is a perspective view of a modification of a hinge in which a biasing member has been incorporated.

FIG. 8 is a perspective view of the biasing member of FIG.

FIG. 9 is a perspective view of another container in accordance with this invention, showing a base section, a cover section and hinge assemblies.

FIG. 10 is a partial sectional view of the container of FIG. 9, showing the cross-section of the base and cover portions of the container and of a hinge assembly.

FIG. 11 is an elevational view of the outer base of the hinge shown in FIG. 10.

FIG. 12 is a horizontal sectional view ofthe hinge of FIG. 11 taken on the plane 12 12 of FIG. 11.

FIG. 13 is a perspective view of another container in accordance with this invention, showing a base section, a cover section and hinge assemblies, one of which has had the hinge removed to reveal the inner construction.

FIG. 14 is a partial elevational view of the container of FIG. 13, with the hinge removed, showing the hinge engaging elements.

FIG. 15 is a partial elevational view of the container of FIG. 13, showing the hinge assembly with the hinge in place.

FIG. 16 is a partial elevational sectional view of the container of FIG. 14 along the plane 16I6, showing the cross-section of the front portions of the base and cover and the anchoring lug portions of the hinge assembly.

FIG. 17 is a perspective view of another container in accordance with this invention, showing a base section, a cover section and hinge assemblies.

FIG. 18 is a perspective view of a portion of the container of FIG. 17 showing the loop portions of the hinge assembly.

FIG. 19 is an eievational cross-sectional view of a portion of the container of FIG. 17 taken on the plane I919 of FIG. 17.

FIG. 20 is a perspective view of the hinge portion of the hinge assembly shown in FIG. 17.

FIG. 21 is a perspective view of another form of the invention, showing a base section, a cover section and hinges anchored into slots in both the box and cover sections of the container.

FIG. 22 is an elevational cross-sectional view of a portion of FIG. 21 taken on the plane 22-22 of FIG. 21.

FIG. 23 is a perspective view of the hinge shown in FIG. 21.

FIG. 24 is a cross-section of a hinge like that of FIG. 23 as originally cast.

FIG. 25 is a partial elevational cross-sectional view of a container of the type in FIG. 21, showing a modification of the hinge assembly.

FIG. 26 is a perspective view of the hinge shown in FIG. 25.

FIG. 27 is a cross-section of a hinge like that of FIG. 26 as originally cast.

FIG.'28 is an elevational cross-sectional view of a portion of a container of the type shown in FIG. 21, showing another modification of the hinge assembly.

FIG. 29 is an elevational view of the hinge shown'in FIG. 28 with the cover partially opened.

FIG. 30 is a cross-section or end view of a hinge like that of FIG. 28 as originally cast.

Referring to the drawings in furtherdetail, a novel container embodying the present invention is shown, either in whole or in part in FIGS. 1'-6, inclusive, which container comprises a tray or base section, a cover section, and hinge assemblies, said hinge assemblies comprising anchoring means which are integral with the box, anchoringmeans which are integral with the cover and a plastic hinge comprising a flexible central section and integral terminal anchor members which are adapted to be inter-engaged and, self-locking with the anchoring means of the base section and the cover section. The entire base section of the container, including the anchoring means which are integral therewith, can be constructed of any desired plastic material either opaque or transparent or semi-transparent. It can be a rigid or semi-rigid plastic material, such as polystyrene, cellulose nitrate derivatives, cellulose acetate, cellulose acetate butyrate,

acrylate resins and thelike. The cover section including Y the anchoring means may alsobe constructed of any one of various materials similarly to the base section. It is advantageous in many cases, particularly for display rial and the base section of opaque material.

The separate hinge is composed of a suitable plastic material having good flexibility and tensile strength and toward the hinge-line and when the hinge is fully in positionthe detents flex up behind the corresponding edge 8 or 9, and thereafter'serve to prevent the cover or base section sliding inwardly off the hinge when the container is fully'open. The functioning of tabs 13 and 14 can beniore fully understood by referring toFIG. 6, which shows the cover of the box 'in open position.

The hinge members 7 being initially formed in the shape indicated in FIGS..2, 3 and 4, and being composed of resilient plastic material, normally urge the cover to closedposition. However, they mayif desired be initially formed in a shape such as normally to bias the cover to open position, and'releasable latch means provided to hold the cover closed. 7 T

. In any case the resilient restoring force may be am? plified by auxiliary'means such as indicated'in the modiback surface .17. and biasing member 18, having a com.- plemental dovetail cross-section, extends the length of groove 16. Biasing means 18 may be made of suitable semi-rigid, resilient; flexible material, for example a plaspossessing high resistance to fatigue failure, for example polyethylene, polypropylene, copolymers of ethylene and propylene, other polyolefin resins, such as l-olefin polymers and copolymers and vinyl resins and the like. Since the hinge may be of a different material than either the cover or the box sections of the. container-,it can be made of a material having ideal properties with regard to tensile strength, flexibility and resistance to fatigue the container but it w1ll be understoodthat normally there and transparency have not had desirable flexibility, tensile strength and fatigue resistance, is overcome by the present invention. Since the hinges are. relatively small, the type of plastic of whichthey are made would not substantially affect the over-all appearance.ofthe'container. Plastic containers of the type contemplated by the present invention may be readily manufactured and assembled, since the components involve simple' construction and since the hinges are easily anchored to the base and cover sections to produce the completed container. v

The embodiment of the present invention shown'in steel.

it would normally assume when unassernbled. Accordingly, the cover is normallybiased to closedposition but as above indicated this effect may be reversed.

' FIGS. 9 to 12 show another'embodiment of the invention. The figures depict one hinge only and fragments of will be a pair of hinges. A container base is indicated at 19 and a cover part at 20, The hinge means includes a lug formatlon integral with'the base which preferably 'is divided into two portions 21a and 21b by a channel 22a. 'The cover similarly has a lug formation integral therewith divided into two portions 23a and 23b by an intervening'channel 22b which coincides with the channel 22a. The channels 22a and '22b enable theaddition of auxiliary stop lugs 24 and 25 to be, formed on the. base 19 and cover 20 respectively; and still produce the base FIGS. 1 too comprises a tray orbase section 1, a cover section 2, and hinge assemblies 3 and 4, hinge assembly 3 being shown disassembled in FIG. 1 to reveal anchoring lug 5 in the form of a boss having laterally projecting means on at least one side and forming an integral part of cover 2, and anchoring lug 6 in the form of a boss having laterally projecting means on at least one side and forming an integral part of base 1. Hinge 7 of the hinge assembly 5 is shown removed. Hinge assembly 4 which is shown assembled is generally similar to hinge 3: and includes similar anchoring lugs 5' and 6. The. f"

anchoring lugs 5 and 6 in the particular embodiment'of the invention shown in FIGS. 1 to 6 areconstructed with an undercut on three sides to form a dovetail cross-section and with'a beveled surface on the fourth side comprising therrespective opposed ends 8 and 9. 1 These beveled sur-v cut frame portion 10 attached to undercut frame portion 11 by a central section of reduced cross-section produced ,by the V-grooves12 defining the hinge line. Detents of .tabs, 13 and 14 are" located on and exltend outwardly from' the'inner surface, 7a of thehinge member 7."f1he undercut frame portions 10 and 11 are: adapted to. engage over and lock with anchoring lugsp5 and 6. H

" In assembling the detents 13 and 14are initially .bentf and 'cover by convenient molding technique. The lug parts 21a, 21b, 23a and 23b are beveled on their edges adjacent the hinge line as indicated at- 26 and 27 and the lug partsare undercut: at their edges opposite the hinge line as indicated at 28 and at their outer edges as indicated at 30 to provide a dovetail as in the case of the form ofFIGS. 1 to-6 The hinge member 31 shown separately in plan view in FIG. 11 and in cross-sectional view inIFIG'. 12 is in the form of a flat rectangular frame, the inner edges around the central openingbeing beveled as shown at 32 to fit the undercut edges of the lugs on the cover and base. V-notches 33 and 33a provide a reduced thickness determining thehinge line." Also cutoutnotches 34 and 34a still further reduce the material at the hingeline and serve the additional functionof facilitating the assembly of.the hinge on the container parts.

It may be notedthat the notches 34 and 34aprovide,

a span across the inner openin g'of the hinge equal to the other containerv part: The. auxiliary lugs'24 and 25 'each actsas 'a' stop against the outer edge of the hinge 31 and ensures against the hinge backing qltfromthe main lugs. if the cover should be. opened to an extreme angle." The auxiliary lugs 24 and 25 require'some additional distor tion of the hinge member 31"in:assembling but because of its flexibility and thin cross-section that can be readily accomplished.

A modification of the form of FIGS. 9 to 12 is shown in FIGS. 13 to 16. In FIG. 13 the hinge is omitted at the right and in FIGS. 14 and 15 to show that a-slot is provided which extends through the wall of the cover '20 and through the lug 4-1, which is thereby divided in two parts 41a and 41b; and that a slot 42 extends through the lug on the base dividing the lug into two parts 43a and 43b. The remainder of the container is like that illustrated in H68. 9 and 10. The hinge 44 is generally of a rectangular frame in shape similar to the hinge 31 of the preceding form. .In assembling the hinge to the container parts the lower half is first applied over the lugs 43a and 43b and squeezed behind the stop lug 45 and-then by compressing together the upper lug parts 41a and 41b the hinge is snapped thereover and behind the stop lug 46 the portions 41a and 41b thereafter returning to their former position to anchor hinge 44 in place. The hinge 42 may be provided with reduced areas at the hinge line similar to that produced by the V-notches in the hinge 31.

FIGS. -17 to 21 show still another embodiment of the invention. In FIG. 17 the container comprises a base part 59 and cover part 51, both of which may be constructed of rigid transparent plastic material, and binge assemblies 52. The hinge assemblies each comprises anchoring loops53 which are integral with cover part 51 and anchoring loops 54 which are integral with the base and which form, respectively, channels 55 and 56. Anchoring loops $3 and 54 are provided with flexible inclined detents or'tabs 57 and 58 respectively. Hinge 59 comprises a strap section 60 and integral end head portions 61 and 62. In applying the hinge 59 it is threaded through the loops 53 and '54 .by flexing the tabs 57 and 58 which then spring back into locking position behind the respective heads 61 and 62. Preferably the strap portion 69 of the hinge is provided with a transverse groove 63 defining a hinge line of reduced thickness.

The forms of containers and hinges thus far described result in containers having walls which are substantially free of openings and capable of holding materials such as powders. Where the matter of holes through the walls is not important other forms may be employed, and FIGS. 21 to 25 show an embodiment of the invention whereby the hinges are connected to both the base and cover parts of the container by means of anchoring means extending through openings in the walls of the container parts. In this embodiment, FIGS. 21 and 22 show a container with a base portion 76 and a cover portion 71 having anchoring slots 72 and 73 respectively, positioned in adjacent relationship to each other whereby hinge 74, having strap portion 75 and anchoring head portions 76 and 77 can be inserted through the respective slots and be anchored in place by means of barbs 78. The hinges just described may be formed advantageously and economically in a long strip of which a cross-section is shown in FIG. 24 and then cut into individual hinge sections. In this form the container is normally biased to open position.

FIGS. 25 to 27 show a modification and the hinge member 39 has a single barb 81 at each end in place of the double barbs which are shown in FIGS. 22 to 24.

FIGS. 28 to 30 show still another embodiment of the present invention. As appears in FIGS. 28 and 29 the container base section 85 is provided with a closed slot 86 and an open notch 87 at each hinge, and cover section 38 is similarly provided with a closed slot 89 and an open notch 90 at each hinge. Hinge 91 has straps 92 and 93 extending through slots 86 and $9, and auxiliary straps 94 and 95 extend through notches 87 and 90 respectively and have ends which engage under a barb or hook 96 and 97 of the respective arms 92 and 93.

Although more complicated in shape the hinges 91 nevertheless may be initially cast in long strip form having a cross-section such as that shown in FIG. 30.

It will be apparent from the preceding description in connection with the drawings, that the present invention encompasses a plastic container which'is particularly well adapted to employ rigid plastic base sections and cover sections and'that each may be of a material appropriate to the desired characteristics and different from the hinge material. The containers of the present invention can be fitted with suitable means for keeping them in a closed .position. However, since these means do not form any overcoming the disadvantages of integral hinges which would sacrifice one or more of these properties for transparency or which would sacrifice transparency in the component in the topor bottom of the box of which they are an integral part in order to obtain flexibility and strength. The arrangement of the present invention also eliminates the necessity for attaching means, such as adhesives, nails, screws and the like and provides containers which are-assembled in an extremely simple manner.

It is to be understood that further modifications and variations of the present invention are possible without departing from the scope of the invention.

We claim:

1. A container having a base section and a cover section and hinge means therefor comprising a separate hinge section of flexible plastic material of high resistance to fatigue failure under repeated flexing, said base section and said cover section being preformed ,with integral loops, each of said integral loops comprising a pair of substantially parallel side walls and a connecting wall, the lower edges of a first pair of said side walls abutting said base section and the opposite edges of said firstpair of side walls abutting a first connecting wall to define a first passage which is substantially rectangular in crosssection, the lower edges of a second pair of said side walls abutting said cover section and the opposite edges of said second pair of side walls abutting a second connecting wall to define a second passage which is substantially rectangular in cross-section, said first passage and said second passage being substantially aligned, said hinge section comprising a strap portion and a plurality of complemental integral enlarged heads, one of which is adapted to be interengaged and self-locking with the loop of said base section and another of which is adapted to be interengaged and self-locking with the loop of said cover section without the aid of auxiliary fastening means, whereby said base section and said cover section are connected together by said hinge section.

2. A container having a base section and a cover section and hinge means therefor comprising a separate hinge section of flexible plastic material of high resistance to fatigue failure under repeated flexing, said base section and said cover section being preformed with integral loops, each of said integral loops comprising a pair of substantially parallel side walls, a connecting wall and a flexible, inclined detent attached to said connecting wall, the lower edges of a first pair of said side walls abutting said base section and the opposite edges of said first pair of side walls abutting a first connecting wall to define a first passage which is substantially rectangular in crosssection and which has two openings, one of said openings being remote from said cover section, a first detent extending in front of the opening in said first passage which is remote from said cover section, the lower edges of a second pair of said side walls abutting said cover section and the opposite edges of said second pair of side walls abutting a second connecting wall to define a second passage which is substantially rectangular in cross-section and which has two openings, one of said openings being remote from said base section, a second detent extending in front of the opening in said second passage which is remote from said base section, said first passage and said 7 second passage being substantially aligned, said hinge section comprising a strap portion and a plurality of 'cornplemental integral enlarged heads, one of which is adapted to be interengaged and self-locking with the loop of said base section and another of which is adapted to be interengaged and self-locking with the loop of'said cover section without the aid of auxiliary fastening means, whereby said base section and said cover'section'are connected together by said hinge section. a

3. A container having a base section and a cover section and hinge means therefor comprising a separate hinge section of flexible plastic material of high resistance to fatigue failure under repeated flexing, said base section and said cover section being preformed with integral anchoring lugs, each of said anchoring lugs being in the form of a boss having four sides, three of which are undercutand the fourth of which has a beveled surface, said anchoring lugs being so positioned on said base section and said cover section that the beveled surface'of one anchoring lug is separated from but opposed to the beveled surface of the other anchoring lug'whereby the assembly of said hinge means is facilitated, said hinge section comprising a'frame having four sides, said frame being adapted to be interengaged and self-lockingwith the anchoring lugs-of said base and cover sections without the aid of auxiliary fastening means, whereby said base sec- '8 section'andsaidcover section that the beveled surface of one anchoring lug is separated from but opposed to the beveledsurface of the other anchoring lug whereby 'the assembly'of said hingemeans is facilitated, said hinge section comprising a frame having four sides, each of which is undercut, said frame being adapted to be interengaged and self-locking with the anchoring lugs of said base and cover sections without the aid of auxiliary fasand said cover section that the beveled surface of one anchoring lug is-separated from but opposed to'the beveled surface of the other anchoring lug whereby the as-- sembly of said hingemeans is facilitated, said hinge section comprising a frame having'foursides, each of which is undercut, and, a back, said frame being adapted to be interengaged and self-locking with the anchoring lugs tion andcover section are connected together by said hinge section. V 1

4. A container having a base section and a cover section and-a hinge means therefor'corn'prising a separate hinge section-of flexible plastic material of high resistance to fatigue failure under repeated flexing, said'base section and said cover section being preformed with integral anchoring lugs, eachof said anchoring lugs being g in the form of a boss having four sides, three of which are undercut and the fourth of which has a beveled surface, said anchoring lugs being so positioned 'on said base of saidbase and cover sections without the: aid of auxiliary fastening means, whereby, said base section and said cover section are connected togetherby said hinge section'a'nd-said anchoring lugs are substantially completely enclosed by the back and four'sides of said frame.

References Citediin the file of this patent FOREIGN PATENTS f $50,275 7 Belgium v Aug. 31', 1956 752,696 France July 24, 1933 

1. A CONTAINER HAVING A BASE SECTION AND A COVER SECTION AND HINGE MEANS THEREFOR COMPRISING A SEPARATE HINGE SECTION OF FLEXIBLE PLASTIC MATERIAL OF HIGH RESISTANCE TO FATIGUE FAILURE UNDER REPEATED FLEXING, SAID BASE SECTION AND SAID COVER SECTION BEING PREFORMED WITH INTEGRAL LOOPS, EACH OF SAID INTEGRAL LOOPS COMPRISING A PAIR OF SUBSTANTIALLY PARALLEL SIDE WALLS AND A CONNECTING WALL, THE LOWER EDGES OF A FIRST PAIR OF SAID SIDE WALLS ABUTTING SAID BASE SECTION AND THE OPPOSITE EDGES OF SAID FIRST PAIR OF SIDE WALLS ABUTTING A FIRST CONNECTING WALL TO DEFINE A FIRST PASSAGE WHICH IS SUBTANTIALLY RECTANGULAR IN CROSSSECTION, THE LOWER EDGES OF A SECOND PAIR OF SAID SIDE WALLS ABUTTING SAID COVER SECTION AND THE OPPOSITE EDGES OF SAID 